For purposes of this disclosure, the term "conductor line" includes conduit, cable, control line, control cable, power cable, hydraulic lines and other conductors of electricity and/or fluids. The term is intended to mean any shielded or unshielded line to conduct electricity and/or fluids that extends from the surface down through the casing to the site of the downhole activity to be performed. The conductor line may be provided with an outer protective shield and internal electrical conductors for the purpose of transmitting electric power to downhole pumps and other electrical apparatus. The shielding may also contain fluid conductors for the purpose of controlling downhole valves and other apparatus. The shield may also include one or more fluid injection lines for various downhole purposes. The shield may also contain any one of a number of combinations of electrical or fluid conductors without departing from the spirit and scope of this invention.
Under circumstances where it is desired to control activities in an oil or gas well, it is a common practice to extend control lines from the surface down to the site of the intended activity. In most cases, the conductor line is attached to the production tubing as the tubing is run into the well, thereby allowing the tubing to provide a certain degree of physical support for the control cable. A number of different clamp mechanisms have been developed for such purpose such as illustrated by U.S. Pat. No. 3,740,801, which shows the connection of single or multiple conductor lines to the tubing.
Oil and gas production tubing is usually interconnected by threaded joints which are established by internally threaded collars that secured threaded extremities of the tubing in assembly. Most oil and gas well tubing sections have a male and female end with the latter being upset so that its diameter is larger than the diameter of the remaining portion of the section. In some cases, tubing is interconnected by conventional box and pin joints that are provided at the enlarged upset extremities of tubing sections. In either case, when the tubing is assembled, it defines spaced enlargements at each of the couplings. When a conductor line is assembled to such tubing, the conductor line must transition each of the many enlarged collars that are defined by the upset couplings in the tubing string. Obviously, as the tubing string is run into the well, these collars tend to contact the inner surface of the well casing. In some cases, sufficient force is developed between the tubing and well casing that the conductor line transitioning the tubing joints is often crushed or otherwise damaged. Where the well is deviated, the curve in the well bore increases the tendency for the tubing to be forced against the inner surface of the casing in the vicinity of the bend as it is installed or removed from the well. It should also be borne in mind that well casing is defined by casing joints that are also interconnected by means of separate couplings. The opposed extremities of the casing sections may be slightly spaced and may define sharp internal edges at the ends of the casing sections. These sharp edges tend to abrade, scrape or tear conductor lines as the tubing and lines are installed or removed from the well. Where the conductor line has a protective coating of elastomeric or plastic material, rubbing the control line against the inner surface of the casing erodes, tears or otherwise damages the protective coating. Damage to the conductor line is even more prevalent where the conductor line is unprotected as it transitions the various couplings of the tubing string.